Oil-water well injection-production effect evaluation method based on production dynamic analysis

Abstract

The invention belongs to the technical field of oil-gas field development, and discloses an oil-water well injection-production effect evaluation method based on production dynamic analysis, which comprises the following steps: determining characteristic parameters of related geology, fluid, engineering, production and the like of an oil-water well injection-production effect to-be-analyzed and evaluated region, and establishing a block overall comprehensive development dynamic numerical value evaluation model according to various characteristic parameters; carrying out yield or pressure simulation prediction on all the producing wells in the block based on the block overall comprehensive development dynamic numerical evaluation model; fitting the predicted yield and the actual yield or the predicted pressure and the actual pressure of the model by adjusting parameters in the block overall comprehensive development dynamic numerical evaluation model; and correcting the bottom hole pressure of the reservoir near each well, obtaining a current reservoir pressure distribution field map, and analyzing and evaluating the injection-production response relationship of the oil-water well. The method has higher timeliness and provides an accurate crack parameter source; describing an initial state of the block overall comprehensive development dynamic numerical evaluation model; and the accuracy of the current reservoir pressure field distribution is further ensured.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and specifically to a method for evaluating the effectiveness of oil and water well injection and production based on production dynamic analysis. Background Technology

[0002] Currently, most domestic water-injection oilfields have entered the high water-cut production stage. However, due to various factors such as geological structure, reservoir heterogeneity, sand body distribution patterns, and injection-production well network distribution, the contradictions between different injection-production well groups and within the same well group become increasingly prominent as the water injection time increases. The prevalence of water injection advantage channels within or between layers seriously affects the sweep range and effective oil displacement efficiency of water injection wells. Therefore, how to correctly analyze and evaluate the injection-production effect relationship of oil and water wells is of great significance for adjusting the injection-production system, densifying local well networks, and improving the recovery rate.

[0003] Current methods for analyzing the injection-production relationship between oil and water wells are mainly based on well network deployment or injection-production data at a certain stage. These methods analyze the relationship by calculating the sweep distance or swept area, and the injection and production rates of injection and production wells. However, these traditional analytical methods cannot consider the heterogeneity of reservoir geological characteristics, the production dynamics of injection and production wells throughout their entire lifecycle, or whether historical measures such as fracturing and acidizing have been implemented, resulting in low accuracy in analysis and evaluation. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method for evaluating the injection and production effectiveness of oil and water wells based on production dynamic analysis. By establishing a dynamic numerical evaluation model for the overall development of the block, and ensuring the accuracy of the model through multiple multidimensional calibration simulations, the overall pressure field of the current block is obtained, and then the injection and production effectiveness evaluation analysis of oil and water wells is carried out.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A method for evaluating the effectiveness of oil-water well injection and production based on production dynamics analysis includes the following steps:

[0007] (1) Determine the relevant geological, fluid, engineering, and production characteristics of the area to be analyzed and evaluated for the effect of oil and water well injection and production, and establish a dynamic numerical evaluation model for the overall development of the block based on various characteristics.

[0008] (2) Based on the dynamic numerical evaluation model of the overall development of the block, the production or pressure of all oil wells in the block is simulated and predicted.

[0009] (3) By adjusting the parameters in the dynamic numerical evaluation model for the overall integrated development of the block, the predicted output of the model is fitted to the actual output or the predicted pressure is fitted to the actual pressure.

[0010] (4) Correct the bottom pressure of the reservoir near each well, obtain the current reservoir pressure distribution field map, and analyze and evaluate the relationship between oil and water well injection and production.

[0011] Furthermore, step (1) includes: establishing a dynamic numerical evaluation model for the overall integrated development of the block, which includes all injection and production wells in the block; simultaneously, establishing a single-well production dynamic analysis model for each well; the production dynamic analysis model provides geological information such as skin coefficient and permeability, as well as engineering information such as fracture length, height, and conductivity for each well to the dynamic numerical evaluation model for the overall integrated development of the block. A structural model is established based on boundary, fault, and layer data, as well as attribute field (P, Ф, K, NTG) data. Combined with the interpretation results of the production dynamic analysis model, fluid PVT parameters, relative permeability curves, and production dynamic information for each well, a dynamic numerical evaluation model for the overall integrated development of the block is established.

[0012] Furthermore, step (2) includes: after the establishment of the dynamic numerical evaluation model for the overall development of the block, the pressure or injection volume of the injection wells is simulated and predicted using the actual injection system of all water injection wells in the block as the injection system of the dynamic numerical evaluation model for the overall development of the block, and the pressure or production volume of the production wells is simulated and predicted using the actual production system of all production wells in the block as the production system of the dynamic numerical evaluation model for the overall development of the block.

[0013] Furthermore, step (3) includes: using geological fracture parameters such as permeability, skin coefficient, fracture length, and conductivity of each well in the overall block development dynamic numerical evaluation model to perform historical fitting between the predicted production or pressure and the actual production or pressure of all injection and production wells in the block. For injection wells with fixed injection volume, pressure fitting is performed; for fixed pressure injection, injection volume fitting is performed; for production wells with fixed production volume, pressure fitting is performed; and for production wells with fixed pressure, production volume fitting is performed.

[0014] Furthermore, step (4) includes: comparing the predicted reservoir pressure near each well after all wells in the block's overall integrated development dynamic numerical evaluation model have completed the historical production data or historical pressure data fitting with the current measured pressure level of the well. If the comparison results are inconsistent, the historical production data or historical pressure data fitting of the block's overall integrated development dynamic numerical evaluation model is performed again until the error between the predicted pressure near the bottom of each production well and injection well and the measured pressure level is within 10%. The current overall pressure field of the block is output, and the injection-production effect relationship of all oil and water wells in the block is analyzed and evaluated.

[0015] Compared with other methods for analyzing the injection-production relationship between oil and water wells, this invention has the following advantages:

[0016] This invention establishes a dynamic analytical model of production for all single wells in a block to obtain current fracture parameters of oil and water wells with a history of fracturing or acidizing. Compared with the fracture parameters obtained using fracturing simulation software, this model is more timely and can provide an accurate source of fracture parameters for the overall dynamic numerical evaluation model of the block's development.

[0017] Secondly, the structural model established based on boundary, fault, layer data and various attribute field information takes into account the heterogeneity of the reservoir and accurately describes the initial state of the dynamic numerical evaluation model for the overall development of the block.

[0018] Finally, based on the historical fitting of production data, this invention further ensures the accuracy of the current reservoir pressure field distribution by comparing the reservoir pressure near oil and water wells obtained from simulation analysis with the actual pressure level results. Attached Figure Description

[0019] Figure 1 This is an analytical flowchart of a method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis;

[0020] Figure 2 It is the production history fitting curve of the single-well production dynamic analytical model;

[0021] Figure 3 It is a construction model;

[0022] Figure 4 These are the relative permeability curves of the block to be analyzed and evaluated;

[0023] Figure 5 It is a dynamic numerical evaluation model for the overall development of the block;

[0024] Figure 6 It is the production history fitting curve of the injection well in the overall comprehensive development dynamic numerical evaluation model of the block;

[0025] Figure 7 This is a comparison of measured pressure data and simulated pressure data from some individual wells;

[0026] Figure 8 This is the distribution of the overall pressure field in the corrected block. Detailed Implementation

[0027] To make the technical problems, technical solutions, and advantages of the present invention clearer, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. However, the scope of protection of the present invention is not limited to the following description:

[0028] Example 1

[0029] This invention provides a method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis, the specific implementation process of which is as follows: Figure 1As shown, it includes the following steps:

[0030] (1) The established dynamic numerical evaluation model for the overall development of the block includes all injection and production wells in the block. At the same time, a single-well production dynamic analysis model is established for each well. The production dynamic analysis model provides geological information such as skin coefficient and permeability of each well, as well as engineering information such as fracture length, height, and conductivity for the overall dynamic numerical evaluation model for the block. Based on boundary, fault, and layer data, as well as attribute field (P, Ф, K, NTG) data, a structural model is established. Combined with the interpretation results of the production dynamic analysis model, fluid PVT parameters, relative permeability curves, and production dynamic information of each well, the overall dynamic numerical evaluation model for the block is established.

[0031] (2) After the establishment of the dynamic numerical evaluation model for the overall development of the block, the actual injection system of all water injection wells in the block is used as the injection system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or injection volume of the injection wells. The actual production system of all production wells in the block is used as the production system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or production volume of the production wells.

[0032] (3) By using the geological fracture parameters such as permeability, skin coefficient, fracture length, and conductivity of each well in the overall block development dynamic numerical evaluation model, the predicted production or pressure of all injection and production wells in the block are historically fitted with the actual production or pressure. For injection wells with fixed injection volume, pressure fitting is performed; for fixed pressure injection, injection volume fitting is performed; for production wells with fixed production volume, pressure fitting is performed; and for production wells with fixed pressure, production volume fitting is performed.

[0033] (4) Compare the predicted reservoir pressure near each well after the historical production data or pressure data of all wells in the overall integrated development dynamic numerical evaluation model of the block with the current measured pressure of the well. If the comparison results are inconsistent, the historical production data or pressure data of the overall integrated development dynamic numerical evaluation model of the block will be refitted until the error between the predicted pressure near the bottom of each production well and injection well and the measured pressure is within 10%. Output the current overall pressure field of the block and analyze and evaluate the injection and production effect relationship of all oil and water wells in the block.

[0034] Step (1) specifically includes:

[0035] A dynamic analytical model for the production of all single wells in this block was established, with information for each well shown in Table 1. Production dynamic analysis was then performed, and the production history fitting curves from the analysis process are shown below. Figure 2 As shown in Table 2, the analysis results provide data support for the establishment of a dynamic numerical evaluation model for the overall development of the block, ensuring the accuracy of the crack parameter sources.

[0036] Table 1 Basic Information on Oil and Water Wells

[0037]

[0038] Table 2 Interpretation Results of Oil and Water Wells

[0039]

[0040] A construction model is established based on boundary, fault, and layer data, as well as attribute fields (P, Ф, K, NTG), etc., specifically as follows: Figure 3 As shown, the pressure (P) data in the attribute field is indispensable. This is combined with the interpretation results of the production dynamics analytical model and the fluid PVT parameters shown in Table 3. Figure 4 The relative permeability curves shown and the production dynamics information of each well are used to establish a system as follows: Figure 5 The diagram shows a dynamic numerical evaluation model for the overall development of the block.

[0041] Table 3 Fluid PVT Parameters

[0042]

[0043] Step (2) specifically includes:

[0044] After the establishment of the dynamic numerical evaluation model for the overall development of the block, the actual injection system of all water injection wells in the block is used as the injection system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or injection volume of the injection wells. The actual production system of all production wells in the block is used as the production system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or production volume of the production wells.

[0045] Step (3) specifically includes:

[0046] By using geological fracture parameters such as permeability, skin coefficient, fracture length, and conductivity of each well in the overall block development dynamic numerical evaluation model, historical fitting was performed on the predicted production or pressure of all injection and production wells within the block against the actual production or pressure. For injection wells with a fixed injection volume, pressure fitting was performed; for injection with a fixed pressure, injection volume fitting was performed. For production wells with a fixed production volume, pressure fitting was performed; and for production with a fixed pressure, production volume fitting was performed. The historical fitting curve of a single well within the block is shown below. Figure 6 As shown.

[0047] Step (4) specifically includes:

[0048] The predicted reservoir pressure near each well in the overall integrated development dynamic numerical evaluation model of the block, after fitting historical production or pressure data of all wells, is compared and corrected with the current measured pressure level of that well. The corrected simulated pressure results are then compared with the measured pressure level results. Figure 7As shown, its error is less than 10%, and the overall pressure field of the current block is obtained as follows. Figure 8 As shown, the bottom pressure of well Q40-18 is low, only 12.4 MPa, indicating that water injection has not been effective. The bottom pressures of wells Q38-20 and Q34-18 are 22 MPa and 25 MPa, respectively, which are not much different from the current formation pressure, indicating that water injection has been effective. The remaining wells are evaluated in sequence using the same method to obtain the injection-production relationship of all oil and water wells in the block.

Claims

1. A method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis, characterized in that, The following steps are involved: (1) Determine the relevant geological, fluid, engineering, and production characteristic parameters of the area to be analyzed and evaluated for the effect of oil and water well injection and production, and establish a dynamic numerical evaluation model for the overall development of the block based on various characteristic parameters; (2) Based on the dynamic numerical evaluation model of the overall development of the block, the production or pressure of all oil wells in the block is simulated and predicted. (3) By adjusting the parameters in the dynamic numerical evaluation model for the overall integrated development of the block, the predicted output of the model is fitted to the actual output or the predicted pressure is fitted to the actual pressure. (4) Correct the bottom pressure of the reservoir near each well, obtain the current reservoir pressure distribution field map, and analyze and evaluate the relationship between oil and water well injection and production.

2. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis according to claim 1, characterized in that, Step (1) includes: the established block-wide integrated development dynamic numerical evaluation model includes all injection wells and production wells in the block, and at the same time, a single-well production dynamic analysis model is established for each well, a structural model is established, and the block-wide integrated development dynamic numerical evaluation model is established by combining the interpretation results of the production dynamic analysis model, fluid PVT parameters, relative permeability curves, and production dynamic information of each well.

3. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamic analysis according to claim 2, characterized in that, The production dynamic analysis model provides geological information such as skin coefficient and permeability for each well, as well as engineering information such as fracture length, height, and conductivity, for the overall comprehensive development dynamic numerical evaluation model of the block.

4. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamic analysis according to claim 2, characterized in that, The construction model is established based on boundary, fault, layered data and attribute fields.

5. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamic analysis according to claim 1, characterized in that, Step (2) includes: After the establishment of the dynamic numerical evaluation model for the overall development of the block, the actual injection system of all water injection wells in the block is used as the injection system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or injection volume of the injection wells, and the actual production system of all production wells in the block is used as the production system of the dynamic numerical evaluation model for the overall development of the block to simulate and predict the pressure or production volume of the production wells.

6. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis according to claim 1, characterized in that, Step (3) includes: using geological fracture parameters such as permeability, skin coefficient, fracture length, and conductivity of each well in the overall block development dynamic numerical evaluation model to perform historical fitting of the predicted production or pressure of all injection and production wells in the block with the actual production or pressure.

7. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis according to claim 6, characterized in that, Historical data fitting involves pressure fitting if the injection well injects water at a constant injection rate, injection rate fitting if the injection well injects water at a constant pressure, production rate fitting if the production well produces water at a constant output, and production rate fitting if the production well produces water at a constant pressure.

8. The method for evaluating the effectiveness of oil and water well injection and production based on production dynamics analysis according to claim 1, characterized in that, Step (4) includes: comparing the predicted reservoir pressure near each well after the historical production data or pressure data of all wells in the overall integrated development dynamic numerical evaluation model of the block with the current measured pressure of the well. If the comparison results are inconsistent, the historical production data or pressure data of the overall integrated development dynamic numerical evaluation model of the block is refitted until the error between the predicted pressure near the bottom of each production well and injection well and the measured pressure is within 10%. The current overall pressure field of the block is output, and the injection-production effect relationship of all oil and water wells in the block is analyzed and evaluated.

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